Allergy season turns brutal as high pollen, heat wave collide

This year’s allergy season turned hellish for sufferers in Eugene and Springfield as a burst of grass pollen collided with a record-breaking heat wave.

Nearly 1 in 4 adults live with seasonal allergies, according to the Centers for Disease Control and Prevention, but how sick someone feels depends on how their immune system responds, which varies widely based on genetics and how much pollen they may be breathing.  

In the southern Willamette Valley — near the “grass seed capital of the world” — residents contend with itchy eyes, sneezing fits and congestion as the bowl-like landscape, surrounded by hills and forests, traps airborne grass pollen close to the ground. 

But pollen wasn’t the only thing trapped over the weekend and into Monday, June 15. Hot, dry air settled in as well, intensifying allergy inflammation. 

An example: bloody noses. Dried-out nasal passages, irritated by pollen, dilate as the nose works to humidify air before it reaches the lungs, increasing strain on blood vessels and making bleeding more likely, explained Kraig Jacobson, co-founder of Oregon Allergy Associates. 

“Some people have been miserable,” he said. “The two biggest factors for pollen and pollen counts are hot dry weather and wind, and we had both.” 

Jacobson’s team uses a special sampler to capture pollen particles and counts it under a microscope, measuring it on a scale from 0 (low) to over 200 (very high). But in recent years, including this one, those readings have pushed well beyond the top of that scale. 

The peak of the season followed a rapid climb last month with 274 pollen particles per cubic meter on May 9, then 776 on May 19, and then 1,005 on May 28, which also came with a stretch of warm weather.

The season began about a week earlier than usual, Jacobson said. His observation aligns with broader national research showing longer and more intense allergy seasons affecting millions of people in the United States. 

In a report released in March, Climate Central — an independent group of scientists — found that warming trends are leading to more days without freezing temperatures, extending the growing season and giving plants more time to seed and pollinate. Their analysis, based on National Oceanic and Atmospheric Administration data, found Eugene is experiencing about 41 more of these days each year, compared to 1970.  

And during peak periods, grasses mature and release pollen at the same time instead of in a staggered sequence, amplifying the intensity of each surge, Jacobson said. This peak may signal the season’s end, though the pollen will be around for weeks to come.  

“This will be our last big hurrah for our pollen,” he said. “Then it’ll drop gradually through the month of June.”